How do the reducing properties change in the Li-Na-K series?

Reducing ability – the ability to donate electrons, it is most pronounced in the most active metals. In chemical elements of one group of the main subgroup of the Periodic Table of Chemical Elements of D.I.Mendeleev, the metal activity increases, and the reducing ability increases due to the increase in the radius of the atoms. Lithium, sodium and potassium belong to the elements of group I of the main subgroup of DI Mendeleev’s table. Consequently, they increase the reducing properties in the Li – Na – K series.